our by law in vancouver states that even if you give an artist permission to put up graffiti on your wall, it has to go. they don't permit graffiti on your walls. whether that's in a mural or whether that's just a tag on your wall. so, even if it is done with permission, with consent, if somebody complains or if one of our by law officers come by, it has to go. and it's one of those very clear definitions of graffiti versus art and that's how vancouver has been doing it. i hope that helps a little bit. >> thank you. yeah, i think here in san francisco the difference between graffiti and art is the permission. i hope i appreciate our anonymously written questions. [laughter] >> all right. anybody else have an answer to that one? so, we'll move on to the next one. i'll take somebody from the audience and come back here. good, i'm seeing some hands go up. we'll go with you, if you want to stand up. >> my question is about liabilities. if you're doing something that the original tagger, the vandal, let's say, did, and now you're using volunteers to paint it out, what -- has anybody consi